The area in yellow is at greatest risk of severe weather on Saturday. The green area could also see thunderstorms, which are not expected to be severe. / Storm Prediction Center

by Doyle Rice, USA TODAY

by Doyle Rice, USA TODAY

Severe weather is likely in the central USA this weekend and into early next week.

Tornadoes, high winds, large hail and flooding rain are all possible as a "powerful springtime weather system" moves across the country, says meteorologist Russell Schneider, the director of the Storm Prediction Center in Norman, Okla.

The outbreak is likely to be the worst of the season so far and may become one of the top severe weather events this year, says AccuWeather meteorologist Alex Sosnowski.

The threat begins Saturday in the central and southern Plains. "South-central Kansas to west-central Oklahoma would be in an elevated risk area for severe weather Saturday evening," AccuWeather meteorologist Scott Breit says.

This includes the cities of Fort Worth, Oklahoma City, Omaha, Tulsa and Wichita, according to the Storm Prediction Center (SPC).

On Sunday, the threat moves into the eastern portions of the Plains and the lower Mississippi Valley. The SPC has placed portions of Arkansas, Louisiana and eastern Texas under a "moderate" risk for severe storms.

Sunday and Sunday night have the potential to be the worst 24-hour period of the outbreak.

About 32 million people are in the risk area for severe storms Sunday, the SPC's Schneider says. "People should monitor the weather closely this weekend and have their severe-weather plans ready."

Large hail and strong tornadoes could extend into Sunday night, AccuWeather predicts. Major cities at risk for violent storms, downed trees and power disruptions Sunday include Kansas City, Mo.; St. Louis; Little Rock; Memphis; Tulsa and Dallas.

The Oklahoma City Memorial Marathon is scheduled for Sunday, and organizers are emphasizing their alert system to notify participants and spectators of approaching storms. There are three parking garages near the start and finish lines where people can take shelter.

Drenching rain could lead to flash flooding and river flooding in some parts of the region, the National Weather Service forecasts, with the heaviest rain likely in Arkansas.

The severe weather threat will shift into the Deep South and Southeast by Monday and Tuesday, with more tornadoes possible, Schneider says.

A "severe thunderstorm" produces hail of at least 1 inch in diameter and/or wind gusting to 58 mph or higher and/or a tornado, the SPC reports.

So far this year, no Americans have been killed by tornadoes. It's been 99 years since the nation has had a fatality-free year as of April 25, reports meteorologist Harold Brooks of the National Severe Storms Laboratory in Norman.

Once the severe threat eases early next week, much of the eastern and southern USA will see a cooler-than-average week, according to the Climate Prediction Center.